Testable technical requirements for safety-critical UI elements, indication of accompanying documentation and training requirements, and traceability to the use specification and use-error analysis.
AMD1:2020 explicitly added hazard-related use scenarios (clause 5.4) as a required third input to the UI specification, alongside the use specification and use-error analysis.
Testable requirements for risk-control-associated UI elements — qualitative requirements and absent traceability to the hazard-related use scenarios list are the most common clause 5.6 deficiencies.
Maps to
IEC 62366: §5.6 Establish USER INTERFACE SPECIFICATION
ISO 13485: §7.3.3 Design and development inputs
Requirement text
The manufacturer shall establish and maintain a user interface specification. The user interface specification shall consider: the use specification (see clause 5.1); the known or foreseeable use errors associated with the medical device (see clause 5.2); and the hazard-related use scenarios (see clause 5.4). The user interface specification shall include: testable technical requirements relevant to the user interface, including the requirements for those parts of the user interface associated with the selected risk control measures; an indication as to whether accompanying documentation is required; and an indication as to whether medical device-specific training is required. The user interface specification shall be stored in the usability engineering file. The user interface specification may be integrated into other specifications. Compliance is checked by inspection of the usability engineering file.
Why this clause exists
Clause 5.6 exists because the user interface design process requires an explicit specification stage that translates usability engineering outputs — user profiles, use errors, and hazard-related use scenarios — into testable technical requirements. Without a user interface specification that is explicitly derived from and traceable to the use specification, use-error analysis, and hazard-related use scenarios, the design process cannot systematically demonstrate that the final interface addresses the identified use-related risks. The testable technical requirements obligation is particularly critical because a non-testable requirement — for example, ‘the display shall be easy to read’ — provides no acceptance criterion for formative or summative evaluation and cannot be verified by inspection. FDA human factors submissions are frequently deficient because the UI specification either does not exist as a discrete document, or exists as a general design specification without traceability to the use-error analysis and without testable criteria for the safety-critical interface elements. The requirement to indicate whether accompanying documentation and training are required formalizes the decision about information for safety at the specification level, ensuring it is addressed before design rather than added as an afterthought during labeling.
What changed
IEC 62366-1:2015+AMD1:2020 CSV clause 5.6 was updated by AMD1:2020. The 2015 edition required the UI specification to consider the use specification and use errors; AMD1:2020 explicitly added the hazard-related use scenarios (clause 5.4 outputs) as a third required input. AMD1:2020 also updated ISO 14971 cross-references throughout and applied defined-term capitalization conventions. The testable technical requirements obligation and the documentation and training indication requirements are unchanged from 2015.
Common gaps (what we see in audits)
- User interface specification absent or not maintained as a discrete document — Many manufacturers have UI design artifacts — wireframes, mockups, design guidelines — but no formal User Interface Specification meeting the clause 5.6 requirements. Design artifacts are not equivalent to a specification because they do not contain testable technical requirements, are not cross-referenced to the use-error analysis and hazard-related use scenarios, and are not maintained under document control as a usability engineering file element.
- UI requirements non-testable or not traceable to risk controls — UI specifications exist but contain qualitative requirements (‘the display shall be clear and readable’) without measurable acceptance criteria, or contain requirements for low-risk interface elements without requirements for the high-risk elements associated with risk control measures.